Nanowires self-assemble from individual particles

Researchers from Oklahoma State University in the US and the Hahn-Meiter-Institut in Germany have developed a method to spontaneously self-assemble luminescent crystalline CdTe nanowires from individual nanoparticles.

Growing the nanowires is a seven-day long process. They form not through point-to-point-initiated vectorial growth but by the recrystallisation of multiple nanoparticles in a linear aggregate that fuses gradually into one crystal. Full details of the growth process can be found in Science.

The nanowires have high aspect ratios, diameter uniformity and optical activity. The researchers claim that the quality and optical activity of the nanowires either exceeds or is comparable to other one-dimensional species produced by more laborious processes.

Exhibiting luminescent quantum yields as high as 29% for green, 16.2% for yellow, 6% for orange and 2.3% for red, the high luminosity of the CdTe nanowires is attributed to their highly ordered crystal structure.

The researchers say the emission wavelength of the nanowire luminescence can be tuned by sizing the original nanoparticles accordingly.

The team believes its method provides a simple technique for the production of 1D semiconductor colloids for processing into quantum-confined superstructures, materials and parts.